#include <iostream>
#define PI 3.14159265
using namespace std;

int main(int argc, char **argv)
{
  double L, R, S;
  std::cin >> L;
  R = L/(2.0 * PI);
  S = PI * R*R;
  std::cout << "R -> " << R << "\nS -> " << S << std::endl;
  return 0;
}